Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging

Fabio Principato, Leonardo Abbene, Gaetano Gerardi, Matthew C. Veale, Giacomo Benassi, Paul Seller, Manuele Bettelli, Andrea Zappettini, Nicola Zambelli

Risultato della ricerca: Article

5 Citazioni (Scopus)

Abstract

Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below (109Cd source) and above (241Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000â...Vâ...cm-1) and good energy resolution at moderate cooling (3.5% and 5% FWHM at 59.5â...keV for the 500 and 250â...μm arrays, respectively) by using fast pulse shaping with a low dead-time (300â...ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10â...ns. For the 500â...μm pitch array (250â...μm pitch array), sharing percentages of 36% (52%) and 60% (82%) at 22.1 and 59.5â...keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250â...kcpsâ...pixel-1), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging (1-140â...keV).This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm coupled to a custom 16-channel digital readout electronics, performing on-line fast pulse shape and height analysis. Charge-sharing investigations were performed, at both low and high fluxes, using fine time coincidence analysis and pulse shape analysis.
Lingua originaleEnglish
pagine (da-a)257-271
Numero di pagine15
RivistaJournal of Synchrotron Radiation
Volume25
Stato di pubblicazionePublished - 2018

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zinc tellurides
cadmium tellurides
Cadmium
Zinc
Pixels
pixels
Fluxes
Imaging techniques
X rays
pulses
application specific integrated circuits
Application specific integrated circuits
x rays
Photons
energy
Detectors
readout
detectors
counting
photons

All Science Journal Classification (ASJC) codes

  • Instrumentation
  • Radiation
  • Nuclear and High Energy Physics

Cita questo

Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging. / Principato, Fabio; Abbene, Leonardo; Gerardi, Gaetano; Veale, Matthew C.; Benassi, Giacomo; Seller, Paul; Bettelli, Manuele; Zappettini, Andrea; Zambelli, Nicola.

In: Journal of Synchrotron Radiation, Vol. 25, 2018, pag. 257-271.

Risultato della ricerca: Article

Principato, Fabio ; Abbene, Leonardo ; Gerardi, Gaetano ; Veale, Matthew C. ; Benassi, Giacomo ; Seller, Paul ; Bettelli, Manuele ; Zappettini, Andrea ; Zambelli, Nicola. / Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging. In: Journal of Synchrotron Radiation. 2018 ; Vol. 25. pagg. 257-271.
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title = "Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging",
abstract = "Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2{\~A}¢...mm-thick CZT pixel detector, with pixel pitches of 500 and 250{\~A}¢...{\^I}¼m, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below (109Cd source) and above (241Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000{\~A}¢...V{\~A}¢...cm-1) and good energy resolution at moderate cooling (3.5{\%} and 5{\%} FWHM at 59.5{\~A}¢...keV for the 500 and 250{\~A}¢...{\^I}¼m arrays, respectively) by using fast pulse shaping with a low dead-time (300{\~A}¢...ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10{\~A}¢...ns. For the 500{\~A}¢...{\^I}¼m pitch array (250{\~A}¢...{\^I}¼m pitch array), sharing percentages of 36{\%} (52{\%}) and 60{\%} (82{\%}) at 22.1 and 59.5{\~A}¢...keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250{\~A}¢...kcps{\~A}¢...pixel-1), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging (1-140{\~A}¢...keV).This work presents the performance of a 2{\~A}¢...mm-thick CZT pixel detector, with pixel pitches of 500 and 250{\~A}¢...{\^I}¼m coupled to a custom 16-channel digital readout electronics, performing on-line fast pulse shape and height analysis. Charge-sharing investigations were performed, at both low and high fluxes, using fine time coincidence analysis and pulse shape analysis.",
keywords = "CdZnTe detectors, Instrumentation, Nuclear and High Energy Physics, Radiation, X-ray and {\^I}³-ray detectors, charge sharing, digital pulse shape analysis, energy-resolved photon counting detectors, high flux",
author = "Fabio Principato and Leonardo Abbene and Gaetano Gerardi and Veale, {Matthew C.} and Giacomo Benassi and Paul Seller and Manuele Bettelli and Andrea Zappettini and Nicola Zambelli",
year = "2018",
language = "English",
volume = "25",
pages = "257--271",
journal = "Journal of Synchrotron Radiation",
issn = "0909-0495",
publisher = "International Union of Crystallography",

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TY - JOUR

T1 - Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging

AU - Principato, Fabio

AU - Abbene, Leonardo

AU - Gerardi, Gaetano

AU - Veale, Matthew C.

AU - Benassi, Giacomo

AU - Seller, Paul

AU - Bettelli, Manuele

AU - Zappettini, Andrea

AU - Zambelli, Nicola

PY - 2018

Y1 - 2018

N2 - Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below (109Cd source) and above (241Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000â...Vâ...cm-1) and good energy resolution at moderate cooling (3.5% and 5% FWHM at 59.5â...keV for the 500 and 250â...μm arrays, respectively) by using fast pulse shaping with a low dead-time (300â...ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10â...ns. For the 500â...μm pitch array (250â...μm pitch array), sharing percentages of 36% (52%) and 60% (82%) at 22.1 and 59.5â...keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250â...kcpsâ...pixel-1), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging (1-140â...keV).This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm coupled to a custom 16-channel digital readout electronics, performing on-line fast pulse shape and height analysis. Charge-sharing investigations were performed, at both low and high fluxes, using fine time coincidence analysis and pulse shape analysis.

AB - Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below (109Cd source) and above (241Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000â...Vâ...cm-1) and good energy resolution at moderate cooling (3.5% and 5% FWHM at 59.5â...keV for the 500 and 250â...μm arrays, respectively) by using fast pulse shaping with a low dead-time (300â...ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10â...ns. For the 500â...μm pitch array (250â...μm pitch array), sharing percentages of 36% (52%) and 60% (82%) at 22.1 and 59.5â...keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250â...kcpsâ...pixel-1), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging (1-140â...keV).This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm coupled to a custom 16-channel digital readout electronics, performing on-line fast pulse shape and height analysis. Charge-sharing investigations were performed, at both low and high fluxes, using fine time coincidence analysis and pulse shape analysis.

KW - CdZnTe detectors

KW - Instrumentation

KW - Nuclear and High Energy Physics

KW - Radiation

KW - X-ray and γ-ray detectors

KW - charge sharing

KW - digital pulse shape analysis

KW - energy-resolved photon counting detectors

KW - high flux

UR - http://hdl.handle.net/10447/253297

UR - http://journals.iucr.org/s/issues/2006/03/00/issconts.html

M3 - Article

VL - 25

SP - 257

EP - 271

JO - Journal of Synchrotron Radiation

JF - Journal of Synchrotron Radiation

SN - 0909-0495

ER -